Steam turbine



0. D. H. BENTLEY.

STEAM TURBINE.

APPLICATION FILED ocT. 18, 1917.

WWW. 28,1922.

@TATES OLIVER D. H. BENTLEY, OF ROSLINDALE, MASSACHUSETTS, ASSIGNOR TOB. F. STURTEVAIIT CGIMPANY, OF HYDE PARK, MASSACHUSETTS, A CORPORATIONOF MASSACHUSETTS.

" STEAM TURBINE.

Specification of Letters Patent.

Patented Mar. 28, 16922.

Application filed October 18, 1917. Serial No. 197,364.

T 0 all whom it may concern- Be it known that I, OLivnr. D. H. BENTLEY,a citizen of the United States, residing at Roslindale, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Steam Turbines; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

The present invention relates to steam turbines.

Owing to the high temperature of the steam there is a very substantialexpansion of the parts and'where a steam conduit of any considerablelength is employed the expansion and contraction due to the variationsof temperature are liable to cause damage to the conduit or to itsconnections. It is one of the objects of the present invention toprovide a team conduit between the steam supply and the nozzle whichshall have rigid connection with these parts and which shall haveprovision between these connections for yielding to compensate forexpansion and contraction due to variations in temperature, thusrelieving the connections of undue strain and preventing liability ofdamage and leakage in the conduit or connections.

Another object of the present invention is to provide a cheap and simpleform of steam supply connection by means of which the steam may bedistributed from a common supply pipe to a plurality of inlet nozzles.

lVith these and other objects in view, as will later appear, the presentinvention con sists in the steam turbine hereinafter described, and moreparticularly defined in the claims.

In the accompanying drawings is illus trated what is now considered tobe a preferred form of the present invention as applied to a well-knownturbine of the impact type. igure 1 is an approximately vertical sectionon lines 11 looking in the direction of the arrows with certain partsshown in elevation, and Fig. 2 is a side elevation looking toward theleftof Fig. 1 with the cover plate and insulating lagging or packingremoved.

In the specific embodiment of the invention illustrated in the drawings,the casing 2 and the head 3 of the turbine are formed of cast iron orother suitable metal. \Vithin the casing is the rotor or bucket wheel lnxed upon the shaft 5 which 1s mounted to turn 111 bearings (ion thecasing '7 of the speed reducing transmission to which the turbine casingis rigidly secured.

Steam is supplied to the rotor through the inlet nozzles formed in thesegments 11 secured to the head 3 of thecasing, which segments areprovided on their inner faces with the reversing buckets commonlyemployed in the type of turbine illustrated in the drawings. The steamis supplied to the nozzles through the steam passage 12 communicatingwith the passage 13 formed in the nozzle valve 14 which is also securedto the head 3 of the turbine casing. This valve is of the usualconstruction, and comprises the valve proper 15 upon the valve stem 16which passes through the valve chamber 17 and stuiting box 18, and isprovided with the handle 19, by means of which the supply of steam canbe controlled as desired. The steam is led to the valve chamber 17through a coiled tube 21, having one end threaded into the valve body'14, and the other threaded into the distributing connection or coupling22, which may be connected with any suitable steam supply pipe.

To avoid loss of heat by radiation, the asbestos lagging or packing 24is provided which surrounds the coiled steam tubular connections 21, theregulating valves, and the major portion of the turbine casing, be ingheld in place by the side cover plate 25, the outer band 26, and theside ring 27.

The steam is exhausted from the bucket wheel into the interior of thecasing 2 whence it passes out through the exhaust port 30. A stuffingbox 31 prevents the escape of steam from the casing around the shaft,the stutfing box being carried by a plate or disk 32 yieldingly clampedon the casing by means of the springs 33 engaging at one end the nut 34:on the threaded stud 35.

The steam passage from the steam supplv pipe is formed in theillustrated GiillXXilment of the present invention in a series ofconnected parts, namel the coupling coiled steam connection 21, valve11-, and nozzle segment 11, each of which may be separately formed ofsteel and assembled to provide a continuous all-steel passage for thesteam. Preferably the rotor t is machined from a solid piece or", steel.By the use oi steel tubing a very efficient and inexpensive connectionmay be provided between the steam supply pipe and the valve casing, a'

coil or loop in the connection permitting il ree expansion andcontraction under the wide variations in temperature which oc cur withthe use of superheated steam without danger oil damage to the steamconnections.

Where the turbine shaft is mounted in bearings in a transmission case,as in the illustrated embodiment of the present invention, and the rotoris thus overhung on the shaft, the use 01. an axially arranged steamsupply pipe permitted, thus a'ffording. a synunetrical distributionsystem or manifold with each nozzle supplied by its own steamconnection. identical with every other connection. A minin'ium size oftub ing for the connections 21 may thus be employed, as each connectionconveys steam for a single nozzle only.

lVhile the present invention has been ill ustrated and described in whatis now considered a preferred en'ibodiment, it is to be mideistood thatit is not limited thereto, but may be embodied in other forms within thescope oi the claims. Moreover, where in certain of the claims loopedtubes are designated, this is not to be taken as limiting the claims totubes having one or more complete turns, but to cover tubes with a bendor loop, whether closed or open, of sufficient extent to permit yieldingot the tube under the variations of temperature without liability oidamage.

Having thus described the present invention what is claimed is:

1. A steam turbine having, in combination, a rotor, a casing, an inletnozzle within the casing, and a steam conduit from the steam supply tothe nozzle and rigidly con nected to said supply and nozzle, the conduitintermediate such connections having provision for yielding to permitexpansion and contraction of the conduit with variations of temperature,thereby avoiding lia bility of damage to said'conduit and connections.

2. A steam turbine having, in combination, a rotor, a casing, an inletnozzle within the casing, and a flexible steam conduit be tween thesteam supply and the nozzle adapted to yield laterally to provide forexpansion and contraction of the conduit with variations in temperature.

3. A steam turbine, having in combination, a rotor, a casing, aplurality of inlet nozzles within the casing, a coupling adapted to beconnected to a source of steam supply, and connections including alooped tube between each of said nozzles and the coupling.

4:. A steam turbine, having in combination, a rotor, a casing, inletnozzleswithin the casing, and a manifold for distributing" steam fromthe steam supply to the nozzl the manifold comprising a plurality orlooped tubes.

5. A steam turbine, having in combination, a rotor, a casing, inletnozzles within the casing, valves on the outside of the casing eachhaving a steam passage connected with the steam passage in the nozzle,and looped tubes between the valves and the steam supply.

6. A steam turbine, having in combination, a rotor, a shaft, bearingsfor the shaft on one side of the rotor, a casing, a steam supplyconnection axially arranged on the side of the casing opposite thebearings, a plurality of inlet nozzles within the casing, a valveoutside the casing for each nozzle, a looped tubular connection betweeneach valve and the steam supply connection, heat insulating materialsurrounding the looped tubular connections, and means tor holding thematerial in place.

OLIVER D. H. BENTLEY.

